Julianne Hough in a Bikini | Pictures

Happy birthday to Julianne Hough, who turns 24 today! The Rock of Ages and Footloose star has had an impressive past few years in Hollywood, first making her mark with a career-sparking job on Dancing With the Stars. She's tackling Hollywood with boyfriend Ryan Seacrest by her side. We're marking Julianne's big day as she continues working on Safe Haven in North Carolina. Happy birthday to Julianne, and click through to see her 24 best bikini moments!